This is a bit embarrassing for me. The answers could be from my own research, eventually. But perhaps someone here has the answer already and others here could also benefit from the information. None of my Cubs have Fast Hitch, but the 1958 140 does have. As far as I know, the hitch point/"spike"/coupling beam for the 140 and the Cub is identical and fully interchangeable. So perhaps some other parts of the system also interchange. Acquired an original (shopworn) Operator's Manual for the 140, 1 014 372 R1, 2-18-63--2B. So the manual is a bit newer than is the tractor. In the Lubrication section, it shows grease fittings at the ends of the lower horizontal bar that supports the hitch receiver. On my tractor, that bar is threaded each end, right-hand threads, and the part 520061R1 is threaded internally for mounting onto the shaft. The assumed, but not specifically stated, purpose is for adjustment of the lifting rods so they will be vertical and to permit rotation as the lift is operated. My parts 520061R1 have no grease fittings and the holes in them are not threaded for such. So one might assume that the original fitting, if any, was a drive fitting. But the two fittings each have different size holes, same part number on both. So two different grease fittings would be required. So I wonder about several things. Does the Cub use the same part at that place on the system? Does the Cub have grease fittings on those parts? What type grease fittings, threaded or driven? Were the grease fittings added as a revision for later production for the system? On the 140, the bar is 1 1/2" diameter. Is the Cub the same or smaller? Is it possible that the early production, which the R1 suggests, was intended to be lubricated by just butting the grease gun up to the hole and giving it a shot that way? The wall of the 520061R1 is thin for threading and any projection of the grease fitting inside would interfere with the threaded ends of the bar.What insight can you offer?

I don't have a 140 so I'm not as familiar with that hitch as I am the Cub hitches. The coupling beam is identical but I doubt much of the rest of the hitch is. In fact, very few parts are even shared between the standard Cub and the Cub LoBoy. The lower horizontal bar is similar in design, with threads on both ends etc. But the one on the Cub is only 1 1/4 diameter. I don't know why they threaded the ends of that shaft. Seems it would have been better to make the shaft a bit longer and cross drill it for a cotter pin. By the way, on the 140 that part is called a lower rockshaft. In a Cub it is called a pull bar support.

My parts books, Farmall 100 dated 6-1-55 and Farmall 100/130/140 dated 9-64, both call out 520061R1 for the lower rockshaft bearing. They both also call out a grease fitting with 1/8" pipe threads and a 67 1/2 degree elbow. The online CaseIH parts catalog calls out the same number for the bearing but substitutes a grease fitting with a 65 degree elbow. So it appears to me that the bearing never changed and all should be tapped for a 1/8" grease fitting. If one of yours has no threads, it may mean that the factory was using self-tapping fittings and yours was never installed. If your other one appears to have a smaller hole, you may have the stub of a broken off fitting still in the hole. Enough cleaning, degreasing and paint removal may reveal that. By the way, the Cub used a 1/8" straight fitting in that location.

The information is appreciated. Thought provoking-- which is good for me. If nothing is done about the grease fittings, it will be no big deal as the tractor is seldom used. But probably the one with the smaller hole will be step-drilled with left hand bits to approach the size of the tap drill for 1/8 pipe. That might break loose any broken stub from a fitting. And if so, one would then know what to expect at the larger hole. I will try to post an update within the next week or so. Things I think about today may not see action for a while. My job list gets longer each day.

Searching eBay, I found two of these corresponding parts said to be for the Cub. Each was listed separately with a photo. The photo for one of them shows a grease fitting and the other does not. The photos do not show directly the place where the fitting is installed. So apparently, broken or missing grease fittings are not unusual for these parts.

Finished the job today-- I hope. Tested one of the castings on the grinder to try to identify the material in the event that welding was desired for any reason. The spark pattern was not typical for cast iron nor for mild steel or cast steel. So it might be a special grade of cast iron. Cast steel welds wonderfully with MIG. But any alternative to welding seems to be best for these parts.Absolutely no visual indication of any fitting on the parts. So started drilling the larger hole, ending with drill "R", the tap drill for 1/8 pipe. Only then did any indication of existing thread appear. Retapped to clear the threads. Then did the other one-- essentially the same results, but the original threads were not perfect. Grease fittings on hand are Straight, 45 deg and 90 deg, no 67 1/2. Rather than half a day and 50 or more miles to find the 67 1/2, the 90 was used as it presents a lower profile than does the 45. Some grease guns might not fit between the bar and the ground for straight fittings. To index the fittings precisely at 90 degrees horizontally to the axis of the lower bar, JB Weld was used on the threads of the fittings. Parts were degreased for the epoxy with brake cleaner spray. Others might have done it differently. But if this does not work, the threads are undamaged and ready for the next attempt at a solution.